Every bodies situation is different. When I started to e bike, I was happy to hardly use the motor at all, but wanted help on the way home from work. Home was 15 all uphill miles, so finding a way to make the battery last all the way there was kind of important. Trading a few seconds of hard pedaling at the lights early in the ride beat running out with 500 vertical feet to go. If it was cold, and the wind was in my face it got real hard to make it all the way home, so I'd start riding slower too, between those lights. Once I got a wattmeter, it got a lot easier to judge my range, how fast I could go on a certain day, etc and make it home. That's when I could measure just how shitty that early motor was at wasting power on a start. With current hub motors all you need to do is pedal moderately to save a lot of power on the starts. But every body is different. After I got all sick, I could not pedal one stroke for about 5 years. At that point is was all up to how fast I rode to save power when I needed to.
What Poider really needs to evaluate his battery capacity, is a watt meter. It can be an expensive but really great cycle analyst, or a cheap watt meter that goes in line from the battery to the controller. Guessing by battery voltage really is a guess, but if you ride the same route every day, you get a feel for where you should be, just by having a volts read out, and and knowing when you need to slow down if volts look low at a certain point compared to normal.